Utilizing tensioned wire ropes or cables, or nets, grids, or fencing made of such cables or reinforced by cables is not suitable in many installations since the capability to accept dynamic stresses is limited. It is not possible to extend the diameter of such retaining cables or reinforcing cables to such an extent that they are capable of absorbing all possible arising forces, due to limitations based on transportation and cost for protective works adjacent roads, railway cuts or the like, for example.
The referenced Swiss Patent 610,631, Bolliger et al, describes a connection for tensioned wire cables, in which a loop is introduced into the cable which is clamped to the cable by clamps which are capable of permitting slipping of the loop portions. If the tension on the cable, rope, typically wire rope, or other tension element exceeds a certain level, the loop portions can slide against each other, and absorb energy applied on the cable. The slippage of the cable, however, is subject to wide variations with a given applied force. Rust, changes in temperature, composition of materials and the like, all affect the capability to absorb overloads.
The referenced Swiss Patent 659,299, assigned to the assignee of the present application, teaches another way; in which a ring-shaped element is coupled to two cable portions which, upon overload, can stretch. The arrangement provides the desired capability to accept overload, however is expensive to install and requires additional cable terminations and connections to the ring element.